Hi there, 

I solve my problem with this code: 

 Int32 docId = Int32.Parse(textBox1.Text.Trim());

                    session = Util.ConexaoRepositorio.buildSessionRepository("NTBSBTI01.arqdigital.local", "Teste", "admin", "a"); //loga no repositório. 

                    docInfo = Document.GetDocumentInfo(docId, session); //busca o documento no repositório com base no ID passado. 
                    docInfo.Lock(LockType.Exclusive);
                    docInfo.GetPageInfo(1); //Pega a primeira página do Documento.

                    String DirBaseApp = AppDomain.CurrentDomain.BaseDirectory;
                    Directory.SetCurrentDirectory(DirBaseApp);
                    string criarDirAtual = Path.Combine(DirBaseApp, "PDF");

                    if (!Directory.Exists(criarDirAtual))
                    {
                        Directory.CreateDirectory(criarDirAtual);   
                    }                    
                   
                    DocumentExporter exportador = new DocumentExporter();
                    exportador.ExportPdf(docInfo, docInfo.AllPages, PdfExportOptions.None, criarDirAtual + docInfo.Name);

                    textBox1.Text = "";
                    
                    axAcroPDF1.LoadFile(criarDirAtual + docInfo.Name);

                    docInfo.Dispose();
                    session.LogOut();