Solvent recovery energy

Waste Treatment Energy = Solvent Recovery Energy =... 

Total solvent recovery energy (MJ) Mass of product (kg) MJ/kg... 

Solvent recovery energy the total energy consumed to recover the solvents used during a chemical reaction, expressed per mass unit of product. 

Process energy and solvent recovery energy are indicators focusing mainly on the level of chemical reaction, while primary energy usage is more industry oriented. The latter may be calculated with respect to the economic value of the product, in line with the Eco-efficiency concept, defined as a ratio of economic and environmental performance. 

Solvent Recovery energy requirements [MJ] kg of final product... 

It is possible to dispense with the extraction step if the oxidation section is operated at high propylene concentrations and low steam levels to give a concentrated absorber effluent. In this case, the solvent recovery column operates at total organic reflux to effect a2eotropic dehydration of the concentrated aqueous acryflc acid. This results in a reduction of aqueous waste at the cost of somewhat higher energy usage. 

Capturing the C02 from fossil-fuel conversion processes. The costs for capturing C02 result from (1) higher investments for the system with C02 capture compared to a system without, (2) the lower efficiency of the process as a result of the operation of the capture plant (e.g., from the additional energy demand for solvent recovery, C02 compression, etc.) and (3) the operational cost for the capture process (e.g., for absorbent replacement). 

Recovery Constraints Distillation is a primary means of solvent recovery. In a separation process the chosen solvent must be easily distilled from the extracted solute. The relative volatility should be large to ensure easy separation. The enthalpy of vaporization should be low for reduced energy consumption. 

A Life Cycle Inventory/Assessment (LCI/A) is used to determine the overall amounts of materials used, waste generated, and energy used during the manufacture of solvents, their use in pharmaceutical processes, and their eventual disposal. Many processes today are designed with an emphasis on solvent recovery to help reduce the costs associated with purchasing fresh solvent and waste... 

Also, successful implementation of a solvent recovery system will depend on the savings it will yield. Although solvent recovery systems can cut down on the purchasing of fresh solvents and waste disposal, they also require an input of energy to operate while producing wastes of their own. If a solvent system is... 

The ROSE process is a solvent deasphalting process with minimum energy consumption using a super-critical solvent recovery system and the process is of value in obtaining oils for further processing. (Gearhart, 1980 Low et al., 1995, Hydrocarbon Processing, 1996 Northrup and Sloan, 1996). 

A hyperfiltration process developed by Mobil Oil, now ExxonMobil, for this separation is illustrated in Figure 5.28(b). Polyimide membranes formed into spiral-wound modules are used to separate up to 50 % of the solvent from the dewaxed oil. The membranes have a flux of 10-20 gal/ft2 day at a pressure of 450-650 psi. The solvent filtrate bypasses the distillation step and is recycled directly to the incoming oil feed. The net result is a significant reduction in the refrigeration load required to cool the oil and in the size and energy consumption of the solvent recovery vacuum distillation section. 

In gas-phase processes, gaseous ethylene or propylene is contacted with solid catalysts, sometimes dispersed in dry polymer powder. The industry uses two different methods of carrying out this reaction, depending on the method of heat removal. In one class of processes, a fluidized bed is used, and in the other, a mechanically agitated dry powder bed is used with evaporative cooling in vertical and horizontal autoclaves. The advantage of a gas-phase process is that no solvent recovery is necessary so that the energy requirement is less. 

Greenhouse gas, kg C02 equivalent, ex energy for solvent recovery kg product Safety kg/kg... 

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