Product transfer between sites using Joint-Y PLS

The product transfer problem refers to that of estimating the operating conditions in a target plant in order for it to yield a final product with the same set of final characteristics as is yielded in another source plant. The estimation of such new operating conditions in the target plant often involves a combination of expertise, rules of thumb and in some cases some fundamental modeling. The use of latent variable modeling using historical data from both sites has been proposed in the past as an alternative approach (C.M. Jaeckle and J.F. MacGregor, Product transfer between plants using historical process data, AICHE J., 46 (2000) 1989–1997). This paper presents a new latent variable regression method: Joint-Y PLS (JYPLS) that is ideally suited for modeling the common latent variable structure in multiple plants. The mathematical foundations for the JYPLS model are presented and several parameter estimation approaches are given. A technique is proposed to solve the product transfer problem using the JYPLS model and two examples are given including an industrial scale-up case for a batch pulp digester from the pulp and paper industry.