The blending process is complicated. The most critical issue is the selection of the optimal combination of components to produce the desired final product. Different hydrocarbon streams are considered while blending stocks using linear and nonlinear programming. This is done to produce chemical products as per various quality specifications and maximize operating profit. This topic will discuss the comparison of linear, indexed linear, and non-linear blending models; examples of nonlinear models; nonlinear qualities; interactive coefficients; nonlinear blending values; reformulated gasoline blend models; pros and cons of nonlinear models; etc.