Long residue processing

Long-Residue Processing in a Riser Pilot Plant... 

There is a major economic incentive to extend the current HC processes to enable heavier feedstocks to be converted to lighter, higher-value transportation fuels. Studies by Idemitsu indicate that iron-modified zeolite catalysts significantly enhance conversion when heavy oils such as long residue are hydroprocessed (65). Nevertheless, major technical barriers exist which make high conversions and product selectivities difficult to achieve with truly heavy feeds (end boiling points beyond 620 °C) - these include ... 

Table 4 presents results obtained when processing a metal-rich vacuum residue of 7° API. Deasphalting this residue with pentane produce a 74% of low asphaltene DAO, which is hydrotreated to obtain a 18°API product with low metal and sulfur content. This product is mixed with virgin VGO to obtain, from the long residue, 30% wt of additional feedstock to FCC that meets metal, nitrogen and Conradson carbon specifications. This operation scheme is economically attractive due to high DAO yield. 

According to the proposed model the decline of the desulfurization activity of a catalyst is governed by the deposition of metals present in the feed. Therefore it is expected that catalyst desulfurization activity is a function of the relative catalyst age 0. This thesis was tested for a set of experiments in which the Caribbean long residue (feed I) was processed over 1.5-mmCo/Mo/ AI2O3 extrudates (catalyst no. R) at various space velocities, viz. U.35, 2.0 and 1.0 kg.kg-Kh-1. 

Clients can react upon the accuracy of the due dates, but also upon the length of the promised lead times. If an order is delivered too late, the client can withdraw the order or stop ordering for some time. Usually the order will not be withdrawn and thus the reaction of the clients towards the accuracy of the due dates can be considered as a long-term process. The reaction of a client upon the length of the promised lead time can be much more direct If a client is not content with the lead time he can address another company, where he may obtain the required lead time. In this section we will consider firm-initiated lead times. The lead times for orders are determined at the end of a period, followed by a decision about the production, where all the orders that arrived during a period obtain the same lead time. We assume that all orders have the same priority. The firm-initiated lead time depends on the number of previous orders which have not been produced, and on the residual lead times of these orders and also on the number of new orders placed during the period. Some of the clients may not be content with the proposed lead time and therefore they may withdraw the order. In this situation, we want to maximise the profit by generating the best lead times. 

Nuclear Waste Reprocessing. Liquid waste remaining from processing of spent reactor fuel for military plutonium production is typically acidic and contains substantial transuranic residues. The cleanup of such waste in 1996 is a higher priority than military plutonium processing. Cleanup requires removal of long-Hved actinides from nitric or hydrochloric acid solutions. The transuranium extraction (Tmex) process has been developed for... 

Screw-pressed oil is aUowed to stand to settle out suspended soUds, filtered through plate filter presses, and then pumped to storage. The oil-rich solvent (miscella) from the solvent-extraction process is filtered or clarified, and most of the solvent is removed in a long tube evaporator. FinaUy, the concentrated oil passes through a stripping column where sparging steam is injected to remove the residual solvent. A metric ton of cottonseed yields ca 91... 

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