INVEST IN THE HUMAN ASSET

Transcription

1 October 2018 INVEST IN THE HUMAN ASSET

2 Jerry Nichols, AGC International, USA, explores a method of downstream waste optimisation that comprises of separation and filtration. All downstream activities in the petroleum industry produce waste, which is dealt with through a wide range of processes. This article will introduce a new method of separation and filtration that is environmentally friendly, inherently safe, efficient and profitable. Recycling There is a vast difference in methods of recycling. While all are better than just disposing of the waste product, some are environmentally and economically better than others. There are three primary definitions of recycling, the first of which is the treatment or processing of used or waste materials to be made suitable for re-use. 1 The most basic example of this is to use waste petroleum products to burn and create energy. The second definition is to alter or adapt for new use without changing the essential nature of the used or waste material. 1 An example of this would be filtering solid particulates and dehydrating waste materials from crankcase oil to be used as a basic bunker fuel oil. The third definition is to use again in the original form or with minimal alterations. 1

3 For example, the distillation and filtration of glycol coolant to be reused as engine coolant. These methods are all good uses of waste materials, are well suited for small volumes, and are simple and inexpensive to utilise. Refining On the other end of the spectrum is the refining process. Waste materials can be transported to an existing upstream processing refinery to be mixed with the raw crude to be re-processed using the original purification method. It is then integrated into the midstream products to be used in downstream consumer products. This method is expensive, with little to no margin. Many operations pay to eliminate their waste materials using this method to meet regulatory disposal requirements. However, it usually involves high transportation costs, and is processed in facilities costing hundreds of millions to billions of dollars. The only reason this method of recycling is feasible is due to the sheer volume of the crude already being processed through the refinery. However, these refineries are usually built near the source of the crude deposits, resulting in high transportation costs. For example, large volumes of waste from as far as North Africa and the Nordic Countries are shipped by intermodal carriers to refineries in Germany to be disposed of. This method of recycling has more to do with conscientious disposal than it has to do with profit optimisation from recycling efforts. Figure 1. AGC Low-Temp Fracturing P&ID. 2 The middle ground In the middle of these extremes lies the world of re-refining. These processes provide the best of both extremes in that they are priced in the tens of millions and can operate at moderate volumes in the to bbl/yr range. Re-refining processes use one or more catalysts to crack the long chain carbons, aid in heavy metal and sulfur removal and help in the separation of waste materials into fractions such as base oil. These catalysts consist of combinations of heat, pressure, chemicals and hydrogen. The process is more cost-effective because of the lower entry cost than a refinery and has a higher product quality than basic recycling. Also, re-refiners often get paid to take the waste and charge for the sale of the final re-refined product, thus making the financial margins higher than the methods described previously. However, expensive conversion stages and hydro-treating costs can make these systems somewhat complicated and economically challenging. Goldilocks process of re-purposing petroleum waste streams In order to optimise the industry s need for a cost-effective process to deal with produced waste, AGC Refining & Filtration has designed the ARR system, which uses a process called Low-Temp Fracturing. This technology uses no process chemicals, or process atmospheric emissions, but rather low pressure and controlled escalating temperature separation. It never cracks the waste material, yet still creates stable re-usable products without the high cost of conversion and hydro-treating. In its most basic form, this process of re-refining petroleum or hydrocarbon-based fluids is a method for separating constituent parts of a waste feedstock individually. First it heats the waste fluid while sealed in a first vacuum chamber to a maximum specified temperature and pressure for the removal of water. Fuel oil is separated from the residual fluid received from the first vacuum chamber by heating the fluid, while sealed in a second vacuum chamber, to a second maximum temperature that is higher than the first specified temperature and at a second specified pressure. Finally, the lubrication oil is separated from the fluid received from the second vacuum chamber by heating the fluid received from the second vacuum chamber, while sealed in a third vacuum chamber, to a maximum specified temperature that is higher than the second maximum temperature and at a third specified pressure. The first, second and third pressures may not necessarily be different. The key to the process is strict control of temperature, pressure and residence time. Used petroleum or hydrocarbon-based fluids, such as lubrication oil, often become contaminated through use due to constituents that degrade, dilute, or otherwise negatively affect the properties of lubrication oil. For example, used lubrication oil can include solid particles, water, hydrocarbon fuel components, lighter oils, dissolved metals, degraded

4 additives, and other contamination components. ARR technology removes this contamination, making a base lubrication oil suitable for reuse in many lubrication applications. While conventional re-refining of used lubrication oil includes superheating and cracking, this system does not crack the waste material, but achieves the same or better results. The technology integrates controlled pressure and temperature on the waste fluid in vacuum chambers, making this system applicable to a broad array of petroleum or hydrocarbon-based fluids, including lubricating oil, fuel, glycol and others. The controlled temperature prevents thermal decomposition of the base fluid during the re-refining process. By starting at the lowest temperature in a full vacuum at a given altitude, it can remove any desired constituent component that is available in waste feedstock starting with water. From there, the temperature is increased in subsequent vacuum reactors to remove constituent components of the feedstock based on their boiling point in a vacuum. For this reason, the number of constituent parts that can be removed from a given waste feedstock is only limited by the number of vacuum reactors each with a given delta in boiling point in a vacuum as precise as 5 C. This allows water, solvent, light fuels, diesel, kerosene, Group I base oil, Group II/II+ base oil, and Group III base oil to all be separated from the same waste feedstock if they are present. Figure 1 is a schematic diagram of an example treatment system for separating a base fluid from a waste fluid. The example system includes three vaporisers or vacuum chambers. Each of the vacuum chambers includes a sealed housing, a fluid inlet, a fluid outlet, and a vaporiser outlet. The sealed housings are pressure-sealed from an ambient environment to enable a specified pressure to be maintained within each of the respective vacuum chambers. Each of the vacuum chambers functions to remove a different constituent made up of one or more components in the waste fluid by heating the fluid to a specified maximum temperature under specified pressure (vacuum) conditions to vaporise the constituent. Vaporisation of the constituent(s) allows it to gather in an overhead portion of the vacuum chamber, producing a pure distillate, where the constituents can be collected and outputted from the respective vacuum chamber through the vaporiser outlet. In a waste fluid that includes a used lubrication oil, the constituents of the waste fluid can vary. For example, some constituents include many contaminants: n Thermal products such as water, soot, carbon, fuel. n Abrasive materials such as road dust, silicates, wear metals like copper and aluminium. n Chemical products such as oxidation products. n Depleted additive remnants such as detergent, antioxidants, anti-wear, pressure agents, friction modifiers, and others. n Other various contaminants. The waste fluid includes a mixture of the base lubrication oil and additives, plus contaminants such as those mentioned above. Thus, the treatment system receives the waste fluid and separates water, solids, heavy metals and other contaminates from the waste fluid in the first vacuum chamber. The remaining dehydrated waste fluid is fed into the second vacuum chamber to remove lighter fractions, such as light fuel oil, diesel and kerosene. The remaining liquid from the second vacuum chamber is fed into the third vacuum chamber and the remaining lubrication oil fraction is volatised, controlling the temperature to mitigate cracking the oil. The resulting distillate includes constituents necessary for base oil. The remaining residual product can be used as an asphalt extender for asphalt operations. The specified maximum temperatures for each of the vacuum chambers can vary based on the constituent(s) that need to be removed from the waste fluid, the pressure in the respective vacuum chamber, the amount of residence time the fluid is heated in the vacuum chamber, as well as other factors. A waste fluid comprising lubrication oil is first heated in a vacuum within a pressure-sealed vessel, by closing automated inlet and outlet valves to and from the vessel, to a maximum temperature less than the critical temperature of water, separating it from the waste feedstock. The remaining fluid is then heated in a vacuum, to a maximum temperature above the vaporisation of the light ends without vaporising light base oils. Finally, the remaining fluid is heated to a maximum temperature to vaporise the desired cut(s) of base oil, but not higher than the cracking temperature of the lubrication oil. It is necessary to keep the temperature of the waste feedstock below 400 C as thermal cracking will have a diminishing return on product quality, while adding unnecessary operating costs. Additionally, since various streams continue to decrease the overall volume of the waste feedstock as it progresses through the system, a default gradual increase in residence time is created, to allow the constituent fluids with higher viscosity and boiling points to process more efficiently. All solid waste contaminates, heavy metals, and water are removed after the first reactor. Solids are removed to nominal 5 μm, water to 5 wppm and heavy metals all to Figure 2. Individual ARR reactor skid.

5 Figure 3. Typical layout of an ARR TM, two base oil cut, re-refining plant. under 1 ppm. All of the dissolved and entrained gases, including H 2 S, are removed throughout the system and neutralised by a NaOH solution at the first stage of the water filtration system. All other constituent components are filtered through various media and polished before being forwarded into their respective holding tanks. This final filtration process removes colour, odour, remaining sulfur and other undesired qualities depending on the constituent fluid being processed at any given part of the system. New vs traditional re-refining methods There are many advantages of the Low-Temp Fracturing process over traditional re-refining methods. First, it is completely modular. All equipment from re-refining reactors to filtration vessels are skid mounted and can be arranged in various configurations. This allows for an increase in the number of constituent items able to be removed, provides the capacity for future expansion, and enables relocation with minimal cost and effort. Therefore, changing a plant s volume, only fractionally increases the cost. For example, a plant volume increase from to bbl/yr would only rise in cost by 60% through the addition of supplementary modules to the system, rather than doubling the cost by buying a second plant. In addition, if solvents require removing as well as diesel from the light cut, an additional skid simply needs to target the solvent instead of leaving it in the low-flash cut. Figure 2 shows an example of an individual reactor skid. As an added benefit, the entire system is a closed loop, removing the pungent smell produced from other methods of re-refining. This method of re-refining also removes the need for a standardised waste feedstock. Many waste streams can be mixed into one and the system operates the same. Volumes or types of constituent parts will vary from reactor to reactor, but the only impact is yield of constituent components. This is due to the incrementally controlled removal of constituent parts. For example, if the plant is processing used motor oil that contains between 5 7% low-flash fuel, and the same quantity of marine slops is added to the waste feedstock which has between 35 40% low-flash fuel, the fuel removed by that designated reactor will increase by approximately 30% with nothing else changing in the system. There is no need to run a separate stream for the different feedstocks, they can simply be mixed together. The process is also both environmentally friendly and inherently safe since there are no process chemicals, no process atmospheric emissions, low temperature and low pressure. Consumed filtration media is designed for maximum lifespan and can be disposed of through commercial incineration. The only byproduct of the process is irrigation quality water. Since the process operates from low temperature to high, and with very low pressure, something unexpected would automatically default to all vapours in the system immediately reverting to their safer and more stable liquid state. This process is fully automated and entirely controlled by a central control room human-machine interface (HMI), running a single ethernet loop, by a single operator. This level of automation and software allows for minute adjustments of hundreds of control and monitoring points to keep the system in a perpetually stable mass balance. If the ethernet loop were to be cut, the system would extrapolate the data and communication from both directions and continue to operate. Figure 3 shows a standard configuration for the entire system, which has an average return on investment (ROI) of months, a small footprint of under 400 m 2 and low operating costs. It can be placed at the source of the waste or the source of consumption, handling common volumes of bbl/yr, thus reducing transportation costs. All of the technology s constituent parts are handled separately and in their unchanged state. This process can be used by a waste collector to make raw materials to sell to a blender or separately to end users. The system could also be placed at a port, collecting bilge slops, hydraulic fluid, or any other petroleum waste and turn it into middle distillate oil (MDO) to go back into the same ships, thus eliminating all the transportation costs. Conclusion Regulations and environmental requirements are continually becoming more restrictive, while transportation and human resource costs are continually rising. There are mid-range volume processing needs that are becoming too expensive to profitably use traditional waste disposal or recycling methods. These needs must be met. New developments are essential not just for the huge industry players, but for everyone, at every volume, and in any industry. References US patents 9,956,499 & 9,957,445.