Recovery Options

The objective of the EU to close material cycles has led to a different understanding and handling of the term waste waste can be regarded as raw material for new after-life options . Bioplastics have been designed on the concept of closed-loop material management-as is found in nature. Bioplastics can be recovered and recycled like conventional plastics by all available methods by thermal recovery, back to plastics, or by chemical recovery. 

Unlike conventional plastics, most bioplastics types can be organically recycled by composting, provided that they comply with EN 13432 criteria. Diverse investigations and studies show that there is no best option in recovery and recycling for plastics. Ecological and economical evaluation results differ with regard to different application of plastics, even if the same resin type is considered. 

Oi anic req ding (composting) The resulting compost is used to improve soil quality and as a replacement for fertilizers. 

Chemical recycling This can be an option, especially for polyester types such as PLA or PHA. By chemical treatment the polymer chain can be de-polymerized, and the resulting monomers can be purified and polymerized again. Suffident amounts of source-separated collected plastic waste are a precondition for application of this method. The same arguments apply for recycling back to plastics. 

---

Chevron s WWT (wastewater treatment) process treats refinery sour water for reuse, producing ammonia and hydrogen sulfide [7783-06-04] as by-products (100). Degassed sour water is fed to the first of two strippers. Here hydrogen sulfide is stripped overhead while water and ammonia flow out the column bottoms. The bottoms from the first stripper is fed to the second stripper which produces ammonia as the overhead product. The gaseous ammonia is next treated for hydrogen sulfide and water removal, compressed, and further purified. Ammonia recovery options include anhydrous Hquid ammonia, aqueous Hquid ammonia, and ammonia vapor for incineration. There are more than 20 reported units in operation, the aimual production of ammonia from this process is about 200,000 t. 

Adsorption and condensation are the normal recovery options. If recycling is considered and is economically feasible, consideration of incinerators as destruction devices may be unnecessary. Generally, recovery units like adsorbers and absorbers result in higher total capital investment than modular, packaged incinerators. 

By cooling the gas is condensed and then available as hydrocarbon feedstock for other processes (some 85% of the MPW input). The light hydrocarbon gas (15% of the MPW input) that remains after cooling is compressed, reheated and returned to the reactor as fluidising gas. It can also be used as a fuel for the cracking process, though other recovery options are being studied as well. 

This paper explores the use of plastics in cars to make them more environmentally friendly. It lists major environmental issues. It then discusses in detail the positive role of plastics during the lifetime of a car (more plastics means less fuel consumption), the fact that automotive plastic parts are user-friendly and safe, the current and future uses of plastics in cars, recovery options for plastics in end-of-life vehicles, mechanical recycling (which is the best recovery option for many large automotive parts), energy recovery (the solution for small plastic parts), and feedstock (or chemical) recycling. Lastly, the way forward is considered. 

This article examines the recovery of automobile shredder residue (ASR), and considers three recovery options ASR as a landfill day cover, ASR in the production of composite materials, and the pyrolysis of ASR to recover chemical feedstock. All are discussed in detail. 

Kubek, D.J., E. Polla, and F.P. Wilcher, Purification and Recovery Options for Gasification, Gasification Technology Conference, San Francisco, CA, October 1996. 

Since pyrolysis converts waste into CO, CH4, and H2, the product gases can be processed in an atmospheric pressure non-equilibrium plasma reformer to improve the energy-recovery potential of the product gas. Energy-recovery options include heat and chemical energy recovery. 

Larger scale DCC units (and associated FCC units) offer greater product recovery options. These are particularly attractive when linked to either an existing or new steam cracker. In such schemes several of the individual unit operations can be combined or substituted by a more efficient system. 

One of the elements of film coating that attracts much attention at technical symposia is that dealing with troubleshooting. This very fact is a clear indication of how poorly the matters described here are considered. While it is certainly important to understand the issues that can potentially lead to problems, and explore recovery options, the very idea that troubleshooting needs to be considered is clearly an admission of failure during... 

Offsite Reclamation Reclamation is the recovery of a valuable material from a hazardous waste. Its techniques differ from use and reuse techniques in that the recovered material is sold to another entity rather than being used in the facility generating it. This option should follow exhaustion of onsite recovery options because of the increase in potential liability, both economic and environmental, with the transportation of waste to the offsite facility. 

Some of the process energy recovery options are discussed in Reference 97. The yield of nitric oxide in Equation 22-20 depends on pressure and temperature as indicated in Table 22.16.97... 

Chemical Composition Information on the chemical composition of solid wastes is important in evaluating alternative processing and recovery options. If solid wastes are to be used as fuel, the six most important properties to be known are 1. Proximate analysis a. Moisture (loss at 105°C for 1 h)... 

In a recent study the PVC content of municipal solid waste for incineration was calculated at approximately 0.8%. In a modern incinerator, energy and HC1 recovery options are attractive (115,146). 

The reasons why incineration is viewed as an attractive recovery option are outlined and environmental challenges facing the incineration industry are considered. The overall European situation with regard to residue generation and processing costs is discussed and the progress being made towards the voluntary commitment of the PVC industry in relation to municipal solid waste incineration and other recovery processes. 15 refs. 

The decomposition of PVC leads to the formation of HCl, which is neutralized by bringing the hot gases into contact with a solid absorbent. This results in a CaCl2-fraction that has to be landfilled. The purified gas is cooled, most of the hydrocarbon condensed as distillate feedstock. The remaining light hydrocarbon gas is compressed, reheated and returned to the reactor as fluidizing gas. Part of the stream could be used as fuel gas for heating the reactor, but as it is olefin-rich, recovery options are underway. 

Seymour, R. Smith, D. The Psychedelic Resurgence Treatment, Support, and Recovery Options, Hazelden Center City, Minnesota, 1993. 

The first part of this paper will present the chemical recovery options for the product spectrum produced by Biocarbons Corporation s reactor system. This is followed by a general discussion and guidelines for chemical recovery from pyrolysis. This paper will also present suggestions for additional research and development to create new high value chemical products and recovery methods. 

The Windows 2000 Startup and Recovery options are relatively straightforward (Figure 14.15). They involve two areas what to do during system startup and what to do in case of unexpected system shutdown. 

Potential hydrocarbon losses from the overpressuring of operating vessels are controlled first by staged computer alerts and/or manual alarms to provide for correction of the condition. If the overpressure exceeds a second set point, pressure relief valves vent the vessel contents to a flare release system. The flare system provides a means of controlled burning of hydrocarbon vapors at a nonhazardous point to avoid fire or explosion risks. Smoke problems from flares are avoided by more efficient designs that use multiple nozzles and low pressure operation to promote clean combustion [57]. Greenhouse gas concerns should more frequently stimulate an interest in energy recovery options from flared hydrocarbons. 

A unique feature of the Lummus/UOP Classic SM process is the noncompressive azeotropic heat recovery option.f In this option, the EB/SM splitter overhead vapor is used to boil an EB-water azeotrope mixture, which is then fed to the dehydrogenation reactors. The condensation of the splitter overhead vapor produces approximately 500kcal/kg styrene. This energy savings potential makes the azeotropic heat recovery option economically attractive, in particular, in regions with moderate to high steam costs. 

Ram, S. EB-SM splitter energy recovery options. In Styrene Conference General Session, Styrene Conference, Prague, Czech Republic, June 22-25, 2003 ABB Lummus Global, Sud-Chemie AG, and UOP EEC, 2003. 

KreiBig J, Baitz M et al (2003) PVC recovery options environmental and economic system analysis. Publicly available report, PE Europe GmbH... 

RESREC Helps evaluate resource recovery options based on waste characteristics and costs, (in use) VP-Expert Micro N. Pandit/WESTON ... 

---